1. Field of the Invention
The present invention relates to an original image processing apparatus for processing original images of books or documents, such as copying machines or facsimile systems.
2. Description of the Prior Art
In conventional copying machines, originals to be copied are exposed to light from light sources such as halogen lamps or fluorescent lamps, and images are formed by light reflected from the originals. Therefore, the image density depends on the brightness of the light sources used for exposing the originals. In order to form images a predetermined density, the light sources must be turned to emit a predetermined quantity of light.
A means has been proposed for automatically controlling the operation of a processing section for forming images in accordance with original image density and for forming high-quality images.
However, since the density of the images depends on the brightness of the light source used, even if the processing section is properly operated, an image of good quality cannot be formed if the quantity of light is not suitable.
In view of the above problem, it has been proposed to detect the quantity of light emitted by a light source and to control the light source in accordance with the quantity of light detected.
It has also been proposed to measure the density of an original image and to control an image formation process in accordance with a measurement of the density of the original image.
However, the provision of sensors for controlling the quantity of light and image formation process are not preferable from the viewpoints of high cost and complexity of the structure.